861. Cortical representation of somatic sensation lies in:
A. Central fissure
B. Pre-central gyrus
C. Post-central gyrus
D. Posterior parietal cortex
E. None of the above

862. Which of the following statement regarding sensory cortex is TRUE?
A. Cells for various sensory modality for a given body part is arranged in columns in the 10 sensory cortex.
B. 20 sensory cortex is found in the sylvian fissure
C. 10 sensory cortex is important for sensory processing regarding position sense & discrimination of size & shape of the objects.
D. 20 sensory cortex is important for learning based on tactile discrimination
E. All of the above

863. Which type of sensation is most affected in the lesions in sensory cortex?
A. Position & fine touch
B. Temperature differentiation
C. Pain
D. Gross touch
E. All are equally affected

864. Which of the following regarding touch sensation is INCORRECT?
A. Touch sensation in the spino-thalamic tract is more concerned with gross tactile localization.
B. Touch sensation in dorsal column is more concerned with localization, spatial & temporal pattern of touch.
C. Touch sensation is transmitted by C fibers.
D. All of the above
E. None of the above

865. Which of the following statements regarding temperature receptors is FALSE?
A. There are more cold receptors in the skin than warm receptors.
B. Temperature sensory organs are naked sensory nerve endings responding to temperature changes
C. Temperatures sensory organs senses subcutaneous temperature, not skin surface temperature
D. Cold receptors respond to temperature range IO-38°C & warm receptors respond to temperature range 30-4SoC
E. A8 & C fibers are responsible for transmission of temperature sensation.

866. Adaptation to temperature changes occurs at:
A. 0-20°C
B. 20-40°C
C. 40-4SoC
D. 4S+oC
E. All of the above

867. Which of the following statements regarding pain sensation transmission is FALSE?
A. Fast or Ist pain is transmitted by A8 fiber.
B. Slow or 2nd pain is transmitted by C fiber.
C. Pain impulses are modified at the dorsal horn by interneurons & collateral touch fibers.
D. Principal neurotransmitter of pain is histamine
E. Pain perception alone do not require a functional cerebral cortex.

868. Which of the following statements is TRUE?
A. Visceral pain tends to be poorly localized & is often referred to distal sites.
B. Visceral pain can initiate reflex contraction of nearby skeletal muscle
C. Ischemic muscle tends to be persistently painful until reperfusion occurs, due to accumulation of metabolic products such as potassium.
D. Visceral afferents travel along the same pathway as the somatic sensory afferents in the spino-thalamic tract.
E. All of the above.

869.Which of the following statements regarding referred pain is INCORRECT?
A. Superficial somatic pain is sometimes referred.
B. Referred pain usually occurs to a structure from the same dermatomal distribution.
C. Referred pain could be due to convergence of peripheral nerve fiber onto spino­thalamic tract, leading to misinterpretation of the site of pain by the brain.
D. Maxillary sinus pain is usually referred to the teeth.
E. All ofthe above

870. Opiods act on the following site to produce analgesia:
A. Opiod receptors on afferent nerve fibers at the site of injury.
B. Presynaptic opiod receptors at the dorsal hom to inhibit release of substance P
C. Rostral sites in brain-stem
D. All of the above
E. None ofthe above